That is a 600 series. Remove handle and plate. To repair it there is a pair of rubber seats and springs that can be replaced. The handle operates a ball, which is also replaceable but not always necessary.

The HARD part is unscrewing the bonnet nut you will see as soon as you remove the handle. Use white vinegar, heat, and a dremel tool, in that order , as necessary to loosen it up. DO NOT put a wrench on it and go to town...the valve body will be damaged beyond repair. ( There is one person in the United States who is known to repair them. Try not to screw it up!)

Jimbo, I am getting ready to replace the seats, springs, ball in my old 600 delta so it won't drip. I'm an electrician, Jim, not a plumber (a little Star Trek humor), so I am a bit nervous on removing the heavily deposited valve body bonnet. The knob screw is stripped and corroded badly so I already know I will have to carefully hack saw the plastic knob off in pieces (have a replacement knob also). I have read your instructions about avoiding the wrench and using vinegar, heat, dremel. What do you intend the dremel to be used for (I do have one). After doing all of those can I periodically attempt a light touch of the wrench to move it? Advice appreciated...

Your ball will have a "diamond" shaped stem, not a round one, aand the white "cam" will have an elongated slot instead of a triangle. Drill the screw holding the handle rather than chopping the handle to bits. If you damage the body, it would probably be cheaper to replace the valve than have me come there to repair it, although I could visit some of my family, and friends, at the same time.

Your ball will have a "diamond" shaped stem, not a round one, aand the white "cam" will have an elongated slot instead of a triangle. Drill the screw holding the handle rather than chopping the handle to bits. If you damage the body, it would probably be cheaper to replace the valve than have me come there to repair it, although I could visit some of my family, and friends, at the same time.

"Hello, can you please help me identify what type of a valve this is and how I can replace it? I attempted to take it apart but it won't budge!